The CD40:CD40L pathway is another highly studied, co-stimulatory pathway that affects both humoral and cell-mediated immunity.

CD40 is constitutively expressed on B-cells, macrophages, and dendritic cells (DC), while CD40L (also known as CD154), is primarily expressed on T-helper cells shortly after activation (although it has also been found on other immune effector cells).

CD40:CD40L binding causes target B-cells to grow and undergo isotype switching. It also causes macrophages to up-regulate their expression of B7 and MHC II proteins, which in turn stimulates the T-helper cells even further.

CD40 is also expressed on most advanced human tumors, and anti-CD40 antibodies are in clinical use for myelomas and leukemias.

CD40L has potential for treatment of other diseases as well. CD40L promotes inflammation and coagulation. CD40/CD40L blockade effectively stops clinical disease progression and CNS inflammation in a mouse model of multiple sclerosis, and also prevents the induction of other autoimmune models such as lupus, arthritis, and autoimmune diabetes. CD40L blockade also shows promise as a treatment to prevent thrombosis following heart surgery and as an immunosuppressant to curb the response to transplanted tissue.

CD40:CD40L involvement in diseases is becoming so popular, that now biotech companies (like BPS Bioscience) are striving to provide highly calibrated CD40 & CD40L recombinant proteins for assay developers and drug discoverers. Interestingly, a wide range of CD40-related immuno-assays (from ELISA to antibody arrays and quantitative protein profiling assays) are also commercially available to make CD40:CD40L studies easier.

Interested in CD40:CD40L interaction or any other specific pathways? Don’t hesitate to leave a message below.